Yul Brynner did not receive an Oscar nomination for portraying the Gunslinger in Westworld.
The film begins with that very interesting concept which is just used to tell a fairly simple story. Most of the time we just watch a few guests hanging around, with the staff being confused by a few malfunctions, with the main focus on two men Peter (Richard Benjamin) and John (James Brolin) on vacation. The highlight of the film without question is Yul Brynner as the aptly named Gunslinger. Brynner in a send up to his role in The Magnificent Seven, right down to almost the exact same costume, plays the constant antagonist for the park guests. Brynner, once again proving that playing villains was his true calling, is quite effective in the early scenes a less serious fiend though. His whole point is to pester the guests until they shoot him in response. Brynner in turn is quite the enjoyable troll as he attempts to mock the men into shooting them, though while doing so Brynner does carry himself with imposing enough to suggest you wouldn't want him as your real enemy. Of course this is only a warm up to the finale of the film when the robots reject all previous programming and are set loose upon the guests.
Brynner's best scenes in the film though are when he confronts the unsuspecting Peter and John, after the systems have gone haywire. Brynner has the Gunslinger take his usual style until he successfully outdraws John and kills him. The smile that Brynner brings to his face is absolutely chilling almost suggesting perhaps a bit of emotion in the Gunslinger's satisfaction in finally killing his target, which makes him quite menacing as he begins chasing down Peter. Brynner throughout the final sequence is pioneering work as the unstoppable villain, apparently influencing Michael Myers and the Terminator. Brynner actually doesn't make it as simple as being a cold face killer. Again those hints of satisfaction in the machine are particularly unnerving, but he does more than that. Brynner also does more in his physical manner throughout the sequence because he actually walks with this very particular outlaw swagger, that is so exact in repetitive is rather off-putting in revealing the mechanical nature of the killer. The point of the performance is the consistency in this portion but there is one great moment in there when Peter hides from the Gunslinger's heat seeking vision by hiding below a torch. Brynner's good in portraying the unnatural switch in the Gunslinger since he does not portray a human confusion, but rather a computer's awkward attempt to break through a glitch. Brynner's work as the killing machine works as making a fierce villain, but he also allude to a bit more when given the chance. The film unfortunately doesn't allow him to explore any more, and does not make much use of what he brings through his performance. Brynner isn't only the best part of the film but his performance alludes towards a better film than the one he's in.